Complex metal salts of phosphoric acid esters and mineral oil compositions containing the same



United States Patent 0 Ferdinand P. Otto, Woodbnry, N. J., assignor to Socony Mobil Oil Company, Inc, a corporation of New York No Drawing. Application October 29, 1955, Serial No. 541,849

20 Claims. ((1252-4315) This application is a continuation-in-part of copending application Serial No. 246,501, filed September 13, 1951,

now abandoned.

This invention relates to improved lubricating oil compositions, particularly mineral lubricating oils for use in internal combustion engines.

As is well known, mineral lubricating oils refined for use as lubricants have a tendency to oxidize in use in an engine with attendant formation of oxidized products which are acidic in character and which exert a strong corrosive action on the engine parts, such as the hard metal alloy bearings. The oxidation of the oil also produces carbonaceous sludge deposits in the engine, particularly around the pistons and oil rings causing them to stick, thus materially lowering the efficiency of the engine.

To counteract these conditions, there have been developed in the art chemical agents which, when added to a mineral lubricating oil designed for use in internal combustion engines, have the ability to inhibit or retard oxidation of the oil. These agents are designated as antioxidants. Other agents have been developed which have dants as well as detergents. This two-fold action of these materials is, of course, of great advantage from an economic standpoint since ordinarily separate additives are employed to impart each of these characteristics to an oil.

It is, therefore, the object of this invention to provide a mineral lubricating oil composition which is stabilized against the formation of corrosive bodies therein during use and which is also fortified as to its detergent ability.

Other and further objects will appear from the following 1 detailed description of the invention.

The additives contemplated herein may be designated broadly as complex metal salts of partial esters of phosphoric. acid. Due to the complex nature of these compounds, no exact chemical formula can be ascribed to them at this time and they are, therefore, best described by the process of producing them.

Broadly, the complex salts of the present invention are prepared by the method which comprises the steps'of l) reacting one mol of phosphorus pentoxide with from about one to about three mols of an organic hydroxy compound selected from the group consisting of a hydroxyaromatic compound that has an alkyl substituent having at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms per molecule, to form an acidic, partial ester of phosphoric acid, and (2) reacting iii a 2,790,766 Ice Patented AP 1957 said acidic, partial ester of phosphoric acid with a metal salt reagent, the metal constituent of which is selected from the group consisting of zinc, cadmium, magnesium, cobalt, barium, calcium and strontium, in an amount sufficient to furnish at least about two equivalents of metal per equivalent of acid-hydrogen content in said acidic partial ester of phosphoric acid, and of which at least about one of said equivalents of metal is furnished by a metal carboxylate selected from the group consisting of metal acetates and metal caproates.

In the practice of the invention, the reaction of the partialester of the phosphoric acid with the metal salt can be accomplished by reacting the ester first with about one equivalent of a metal saltreagent which may be a metal carboxylate or a salt other than a metal carboxylate, such as a metal hydroxide, metal carbonate or metal alcoholate, this reaction being followed by reaction with about one equivalent of a metal carboxylate, such as a metal formate, acetate or caproate, the metal constitutent of which is the same as that of the reagent utilized in the first reaction. However, more than one equivalent of the metal salt reagent can be utilized in the first step, amounts up to and including about two equivalents or more being entirely suitable. It will be understood, therefore, that the use of about one equivalent of the metal salt reagent in the firstreaction and about one equivalent of metal carboxylate reagent in the second reaction represents about the leastamounts of these reagents which can be successfully employed. Obviously, in instances where a metal carboxylate is used in the first reaction and more than one equivalent is employed the second reaction will not require an additional full equivalent of the reagent but only an amount thereof necessary to supply up to a minimum of two equivalents of metal. Thus, alternatively, the reaction of the partial ester with the metal salt reagent may be conducted in a single step by utilizing at least about two equivalents of metal carboxylate exclusively. Here again, this represents about the least amount which can be used. It can be said then that the upper limit with respect to the amounts of the several metal salt reagents which can be employed is not a critical factor but is governed largely by practical considerations. Thus, although the use of amounts considerably higher than those above indicated provides no particular advantage the employment of large excess amounts of the salts reagents tends to reduce the fluidity of the reaction mass which, in turn, may create handling and filtration difiiculties.

The complex metal salts herein contemplated have metal contents substantially greater than normal salts of the phosphoric acid' partial esters. Generally, these complex salts contain at least about two equivalents of metal per equivalent of acid-hydrogen in the partial ester. We have found that these complex metalacetate salts when utilized in mineral lubricating oils provide outstanding detergent properties in the oil. They also generally improve the antioxidant properties of the oil.

We are aware of the fact that the normal metal salts of the organo-substituted phosphoric acids have been disclosed heretofore as oil additives. Patents Nos. 2,228,658 and 2,228,659 to B. B. Farrington et al. and No. 2,228,671 to George L. Neeley, for example, describe normal metal salts of this type and oil compositions thereof. However, in so far as is known there has been no disclosure in the art of complex metal salts of the type herein contemplated, or that these complex metal salts possess markedly improved detergent powers in lubricating oils over the normal salts. Since the complex metal salts have not been known heretofore, they are believed to be new compositions of matter.

As aforesaid, due to the complex nature of the reactions involved in the formationof the complex metal salts, their exact structure has not as yet been deterr mined. However, in order that the nature of these products may be understood to the fullest possible extent, and without intending to limit the invention in any LCBHIT P O--Zn(C2HsO7) way, the following theoretical observations may be made. When an alkylated hydroxyaromatic compound, such as an alkyl phenol reacts with phosphorus pentoxide in a 3:1 mol ratio, indications are that the product obtained plex type rather than the latter possibility. Thus, it is consists essentially of a mixture of (l) monoalkaryl possible to prepare products containing more than two phosphoric acids, (2) di-alkaryl phosphoric acids and 1t) eq i 9f Zinc A150, a normal Zinc Salt of the (3) pyrophosphoric acids. These products may be repphosphoric acid ester, prepared with a basic salt reagent resented by the following formulae in which R represents other than zinc acetate, such as zinc hydroxide, zinc the organic (alkaryl) substituent. carbonate, zinc alcoholate, etc., may be further reacted (1) O with zinc acetate to form products similar to those obll tained by treatment of the ester with two equivalents of However, indications are that the structure is of the com- R zinc acetate. (2) E ALKYL HYDROXYAROMATIC COMPOUND (ROMP- 0H The preparation of the compounds of the invention involves, first, the alkylation of a hydroxyaromatic compound, such as phenol. Alkylation of the aryl hydroxide may be accomplished by methods known to the art, such as OH 011 by a Friedel-Crafts synthesis using a halogenated hydro- The relative proportions of these compounds present Carboll- The fllkylatloh y also be effected by reaction in the product would be expected to be governed to some 0f the M3 hydroxide With unsaturated hydwcafbohs, extent by the proportions of hydroxyaromatie compound or alcohols, in the presence of a suitable catalyst, such and phosphorus pentoxide used in. the reaction. For as 4, 3, example, when the mol ratio of the hydroxyaromatic yp y hydl'oXides which y be used as the compound to phosphorus pentoxide is 3:1, the aj starting material for the alkylation reaction are: phenol, components of the reaction product are considered to be TCSQYCihOL hydfoqllihohe, Catechol, cre501, Xylem], ymost probably the monoand di-esters of phosphoric y p yh heflZyl Phenol, P y ethyl P acid with minor amounts of pyrophosphoric acid. Phchfil resins, y y y p y guaiacol, alpha We have found, for example, that when the octyland beta llaphlhol, alpha and beta methyl haphthol, {013/1 phenol-phosphorus pentoxide product is reacted with an naphthol, y y Ilaphthol, hehZyl haphthol, ahthl'flhol,

amountof zinc acetate at least twice that which would P y methyl haphthol, Phehathrol, chlorphenhl and lhh be equivalent to the acid-hydrogen of the said product, like- Preference in general is to the mOhOhYdFOXY P the resulting salt will contain at least about two, and as r1015 Otherwise unsubstituted, Particular Prefertihce being high as three, equivalents of zinc per equivalent of acidity g n to Phenol and 61119112l and beta hflphtholin the octylphenol-phosphorus pentoxide product. Al- Th6 hifdroxlfilmmfll'ic tmay haw though, as stated previously, the structure of the 40 several alkyl groups attached to the nucleus thereof. in plex metal salt products is not known, it is believed that y lhe alkyl Ehrlich-0f this COmPOUHd ShQUld the extra equivalents of zinc are incorporated i to the tain a total of at least eight carbon atoms. Thus, if the m l ule through a coordination or complexing of the alkyl substituent contains less than eight carbon atoms, Zin alt with the normalzinc salt of the phosphoric the aromaticnucleus should contain more than one such acid ester, Thus, the reaction of zinc acetate with octyl- 45 substituent to bring the carbon atom content of the side phenol-phosphorus pentoxide (3:1) product in the prochains so attached to about eight in order to provide ultiportion of about two equivalents of zinc acetate per mate complex salts which are completely oil soluble. acid-hydrogen equivalent of the octylphenol-phosphorus On the other hand, the hydrocarbon from which the pcntoxide product may be represented as follows: alkyl group is derived may suitably contain up to 30 or Another possible structure for these products would be even 40 carbon atoms. In fact a preferred source of the that corresponding to a mixed acetate-phosphate zinc alkyl substituent is petroleum wax which contains hydrosalt. This product, when employing the octylphenolcarbon molecules having from about 20 to about 3 phosphorus pentoxide (3:1)v product, would be reprecarbon atoms and an average of about 24 carbon atoms sentedas follows: i per molecule. Other suitable alkyl hydroxyaromatic compounds are, for example, octylphenol, diamylnhenol,

3 Zn (62mm) 7 decylphenol, laurylphenol, tetratlecylphenol. hexadecylphenol and octadecylphenol, octylphcnol being particu- O-Zn-(CzHaOz) larly preferred.

Where a primary aliphatic alcohol is used for reaction h with phosphorus pentoxide, rather than an alkaryl hy- 5 droxy compound, itshould likewise contain at least about Cs n Scarbon' atoms and suitably as high as 20, oreven 30, carbon atoms. Of the alcohols suitable for use in the invention there may be mentioned, as non-limiting examples, the following: octyl alcohol, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, carnaubyl, ceryl and melissyl alcohols. Unsaturated alcohols, such as oleyl alcohol, may also be used.

The various alkylphenols and aliphatic alcohols utilized in the invention, with the exception of the wax-alkylated phenols, are either available commercially or the methods for their preparation are within the skill of those versed in the art. The preparation of a wax-alkylated type of product, however, is illustrated by the following procedure.

WAX-PHENOL A parafiin wax melting at approximately 120 F. and predominantly comprised of hydrocarbons, having at least 20 and an average of about 24 carbon atoms in their molecules, is melted and heated to about 200 F., after which chlorine is bubbled therethrough until the wax has absorbed about 14%, by weight, of chlorine. A sufficient quantity of this chlorinated wax to provide three atomic proportions of chlorine is then heated to a temperature varying from just above its melting point to not over 150 F. One mol of phenol (CeHsOH) is then mixed with the chlorowax. The mixture is thenheated to about 150 F. and a quantity of anhydrous aluminum chloride, corresponding to about 3% of the weight of the chlorowax in the mixture, is slowly added with active stirring. The rate of addition of the aluminum chloride should be sufliciently slow to avoid violent foaming and during the addition the temperature should be held at about 150 F. After the aluminum chloride has been added, the temperature of the mixture may be increased slowly over a period of from 15 to 25 minutes to a temperature of about 250 F. and then should be more slowly increased to about 350 F. To control the evolution of HCl gas, the temperature of the mixture is preferably raised from 250 F. to 350 F. at a rate of approximately one degree per minute, the whole heating operation occupying approximately two hours from the time of adding the aluminum chloride. If the emission of HCl gas has not ceased when the final temperature is reached, the mixture may be held at 350 F. for a short time to allow completion of the reaction. However, to avoid possible cracking of the wax, the mixture should not be heated appreciably above 350 F., nor should it be held at that temperature for any extended length of time.

It is important that all unreacted, or non-alkylated phenol remaining in the reaction mixture, as well as aluminum chloride, be removed. This can be conveniently effected by washing the product several times with a mixture of water and an alcohol, such as 'butanol, preferably at elevated temperature, say 175 F. The product may then be treated with steam. This latter step will insure complete removal of the unreacted material and also dry the product.

It will be understood that a wax-substituted phenol prepared according to the above procedure in which a quantity of chlorowax containing three atomic proportions of chlorine and having a chlorine content of 14% is reacted with one mol of phenol is designated as waxphenol (3-44)." Similarly, wax-phenol (3-10) and wax-phenol (140) may also be prepared by the reaction of sufiicient amounts of chlorinated wax, containing by weight, of chlorine, to provide three atomic proportions and one atomic proportion of chlorine per mol of phenol, respectively, in the reaction and are useful in the invention. In general, the amount of chlorowax, containing from about 10% to 18%, by weight, of chlorine, used in the reaction is suflicient to supply between one and four atomic proportions of chlorine per mol of phenol used.

PARTIAL ESTER OF PHOSPHORIC ACID In preparing the alkaryl phosphoric acid ester, the alkyl hydroxyaromatic compound and the phosphorus pentoxide are heated together at a temperature of from about 50 C. to about C. for a period of time to insure substantially complete reaction, usually from about 5 to 15 hours. An inert solvent, such as toluene, xylene or the like, may be used to facilitate the reaction. A mineral oil may also be conveniently used as the solvent, in which case the product is an oil concentrate which may be used directly in the preparation of the ultimate complex metal salt. In this way, the ultimate complex metal salt product is obtained in the form of an oil concentrate and may be conveniently utilized as such for addition to mineral lubricating oils. Where a solvent other than mineral oil is used, the reaction mixture is filtered and topped at elevated temperature and reduced pressure to remove the solvent.

The proportions of alkyl hydroxyaromatic compound and phosphorus pentoxide used in the reaction can be varied between from about one to about three mols of the alkyl hydroxyaromatic compound to one mol of phosphorus pentoxide, although our preferred products are obtained by the use of about three mols of the alkyl hydroxyaromatic compound (or alcohol) per mol of phosphorus pentoxide.

COMPLEX METAL SALT As indicated previously, in preparing the complex" metal salt of the phosphoric acid ester, a salt of the ester may first be prepared by reaction of the ester with a suit able metal salt, such as a hydroxide, carbonate, alcoholate, etc., and the desired complex salt then formed by further reaction of the ester salt with a metal carboxylate, preferably the acetate, of the same metal constituent as the metal salt reagent used in the formation of the ester salt. On the other hand, the desired complex salt may be prepared directly by reacting the ester with a sufficient amount of a metal acetate salt to provide more than the amount of metal which would be equivalent to the acidhydrogen content of the phosphoric acid partial ester. This direct one-step procedure is generally preferred.

The reactions required to produce the complex salts by either the indirect method, i. e., by first forming the ester salt or by forming the complex metal salt with the metal acetate reactant directly, are within the skill of those familiar with the art, both reactions being accomplished at temperatures of from about 50 C. to about 200 C. and in a relatively short time, generally from about onehalf hour to two hours. As already stated, the total amount of metal salt reactant used in forming'the com plex salt by the indirect method (-i. e., through initial formation of the ester salt) and by the direct method, should be suificient to provide an amount of metal which will completely replace the acid-hydrogen of the phosphoric acid ester and also supply the additional amount (at least equivalent to that required to form the ester salt) of metal necessary to form the complex metal salt product; the complex salts generally containing at least about two equivalents of metal for each equivalent of acid-hydrogen in the phosphoric acid ester. A suitable solvent medium, such as benzene, toluene, xylene and the like, or a mineral oil may be used as the solvent. In the latter case, an oil concentrate of the complex salt is obtained.

We have found that, in forming the zinc complexes, it is more convenient and economical to supply the zinc acetate to the reaction in the form of zinc oxide and glacial acetic acid.

The following specific examples and test results will serve to fully illustrate the nature and outstanding utility as oil additives of the complex salts herein contemplated.

7 Example 1 WAX-PI-IENOL (31&) P:O.-. (3:1) PRODUCT Reaction mixture:

Wax-phenol (3-14) (phenol content=approx.

11 .9%) "grams" 300 P205 do 18 Toluene ml 300 Procedure.-The wax-phenol (3-14) and toluene were placed in a 2-liter, 4-necked, round-bottom flask containing a reflux condenser, thermometer and mechanically driven stirrer. After heating to 100 C., phosphorus pentoxide was gradually added to the mixture over a 4-hour period. Following this, the temperature of the mixture was held at 100 C. for a period of 8 hours to insure complete reaction. The product Was then filtered through filtering clay and the filtrate was topped to 150 C. under diminished pressure to remove the toluene solvent. The residue, representing the finished product, contained 2.2% phosphorus and had a neutralization number of 48.

Example 2 NORMAL ZINC SALT OF WAX'PHENOL (3-14)-P2O5 (3:1) PRODUCT Reaction mixture:

Wax-phenol (344)4205 (3:1) product (Ex. 1)

grams 100 Zn(C2H3O2)2.2H2O d 9.5

Mineral oil (3. U. V. of 296 sec. at 100 F.;

solvent-refined Penna. oil) grams 300 Ethyl alcohol ml 100 Procedure-The wax phenol (314)-phosplrorus pentoxide (3:1) product. and the mineral oil were placed in a 2-liter, 4-necked. round-bottom flask equipped with a reflux condenser, thermometer and a mechanically driven stirrer. The zinc acetate dihydrate was dissolved in the ethyl alcohol and the solution added to the other reactant at room temperature. The reaction mixture was heated, removing alcohol by distillation to 175 C., and held at that temperature for one hour. After cooling, the reaction product was dissolved in benzene and the solution filtered through a Buehner funnel packed with filtering clay. The zinc salt was recovered as the distillation residue by topping to 175 C. under diminished pressure. This material contained 0.78% zinc and 0.52% phosphorus.

Example 3 \\.1X-I'IIE1\'()L (31-l-)J72Os (3:1) PRODUCT Reaction mixture: Grams Wax-phenol (3-14) 1000 Mineral oil (S. U. V. of 296 sec. at 100 F.;

solvent-refined Penna. oil) 2000 P205 M 60 Example 4 COMPLEX ZINC ACETATE SALT OF \VAX-PHENOL (3.l-l)l20s (3:1) PRODUCT Reaction mixture:

Wax-phenol (3-14)-P2O5 (3:1) product (Ex. 3)

grams 400 Zn(CzH3O2)2.2H2O do 30.6 Ethyl alcohol, Formula 30 1 ml 175 1 A denatured alcohol containing 10 gals. pure methanol per 100 girls. 190 proof ethyl alcohol.

Pl'0cedure.--The wax-phenol (3l4)-phosphorus pentoxide (3:1) product was added to a 1-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer, and mechanicallydriven stirrer. The zinc acetate dihydrate was dissolved in formula alcohol and the solution added to'the reaction flask at C. The reaction mixture was heated with agitation and a nitrogenflush to remove alcohol and aqueous acetic acid andthen held at the attained temperature of 165 C. under diminished pressure for one hour. The reaction product was cooled to C. and filtered through filtering clay on a heated Buchner funnel. The filtrate representing the finished product was a dark amber liquid containing 2.64% zinc and 0.75% phosphorus.

Example 5 OCTYLPHENOL-PaOs (3 1) PRODUCT Reaction mixture: Grams Octylphenol 800 P205 180 Example 6 NORMAL .ZINC SALT OF OCTYLPHENOL-PzOa (3:1) PRODUCT Reaction mixture: Grams Octylphenol-PzOa (3:1) product (Ex. 5) 400 Mineral oil (SJU. V. of sec. at 100 F.;

acid-refined Mid-Continent) 800 ZnCO: 94

Pr0cedure.--The octylphenol-phosphorus pentoxide (3:1) product and the mineral oil were placed in a 3-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer.

The zinc carbonate was added gradually over a 15-minute period and the mixture heated to and maintained at 100 C. for two hours. The reaction product was filtered through filtering clay contained on a heated Buchner funnel giving a product containing 3.90% zinc.

Example 7 COMPLEX ZINC ACETATE SALT 0F OCTYLPI'IENOIrPzOs 3:1 PRODUCT Reaction mlxture:

Octylphenol-P2O5 (3:1) product (Ex. 5)

grams 400 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) grams 800 Zn(C2HzO2)2.2H:O do 329 Ethyl alcohol, Formula30 ml 1450 Procedure-The octylphenol-phosphorus pentoxide (3:1) productand the mineral oil were placed in a 5' liter, 4-neeked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and were heated with agitation to 70 C. The

Zn(C2H3O2)2.2H2O

was dissolved in the formula 30 alcohol and the solution I as added at 60 C. to the reaction flask. The mixture was then heated to C. allowing alcohol and aqueous acetic acid to distill. After three hours at this temperature, the last two hours under diminished pressure, the reaction product was filtered through filtering clay contained on a heated Buchner funnel. The filtrate contained 8.35% zinc and 2.73% phosphorus.

Example 8 acid-refined Mid-Continent) 13.0 Zinc oxide 3.98 Acetic acid (glacial) 6.17

Prcedure.--The octylphenol-phosphorus pentoxide (3:1) product and mineral oil were mixed in a S-gallon glass lined kettle equipped with a mechanical stirrer and heated to 146 F. Acetic acid was then added followed by zinc oxide. Upon heating to 238 F., at which point refluxing began, a nitrogen stream was introduced to facilitate distillation of acetic acid. The temperature was then raised to 330 F. and held there for two hours at atmosphere pressure and one-half hour under diminished pressure. After cooling to 190 F., the reaction product filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 10.55% zinc and 3.38% phosphorus.

Example 9 NORMAL ZINC SALT OF OCTYLPHENOLPzOs (3:1) PRODUCT Reaction mixture: Grams Octylphenol-PzOa (3:1) product (similar to Example 5, but N. N.==2l2) 600 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 600 ZnCOs 156 Procedure-The octylphenol-phosphorus pentoxide 3:1) product and mineral oil were mixed in a -liter, 4- neck, round-bottom flask equipped with a condenser, thermometer, and a mechanically driven stirrer. Zinc carbonate was added at 650 C. and the mixture was heated to 100 C. with a nitrogen flush and held at 100 C. for two hours. The reaction mixture was pretreated with 5%, by weight, of filtering clay and then filtered through filtering clay contained on a heated Buchner funnel. The filtered product contained 5.55% zinc.

Example COMPLEX ZINC ACETATE SALT OF OCTYLPHENOL-Pzos (3: 1) PRODUCT Reaction mixture: Grams Normal zinc salt of octylphenol-IzOs (3:1)

product (Ex. 3) 150 ZnO (charge on basis of N. N. of octylphenol- P205 product used in Ex. 9) 13.6 Acetic acid (glacial) 20.2 H2O 34.0

Pr0cedure.-The normal zinc salt of octylphenol-phosphorus pentoxide (3:1) product was placed in a 500-ml., 4-neck, round-bottom flask equipped with a distillation assembly, a submerged gas inlet tube, a thermometer, and a mechanically driven stirrer, and was heated with agitation. When the temperature reached 70 C., aqueous Zinc acetate, prepared by heating zinc oxide, acetic acid and water to 90 C., was added directly and the heating rate increased. Nitrogen was introduced at 125 C., aiding removal of acetic acid and water, and the reaction temperature of 165 C. was reached within 1% hours after the Zn(C2HaO2)2 (Aq.) addition. The reaction mixture was held as 165 C. under diminished pressure for an additional hour. The reaction product was pretreated at 100 C. with 4%, by weight, of filtering clay and then filtered through 1%, by weight, of the clay contained on a heated Buchner funnel. The filtrate representing the finished product contained 12.58% zinc and 3.46% phosphorus.

Example 11 COMPLEX ZINC ACETATE SALT OFOCTYLBHENOL-PnOs (3: 1) PRODUCT Reaction mixture: Grams Normal zinc salt of octylphenol-PzOe (3:1)

product (Ex. 9) 150.0

ZnO (charge of Zn based on Zn content of Ex. 9) 10.4 Acetic acid (glacial) 14.4 H2O 24.8

Pr0cedure.The normal zinc salt of octylphenol-phosphorus pentoxide (3:1) product was placed in a 500-ml., 4neck, round-bottom flask, equipped with a distillation assembly, a submerged gas inlet tube, a thermometer and a mechanically driven stirrer and was heated with agitation. When the temperature reached C., aqueous zinc acetate, prepared from zinc oxide, acetic acid and water heated to C., was added directly and the heating rate increased. Aqueous acetic acid was recovered by distillation during attainment of the reaction temperature of 165 C. and this temperature was held, with a nitrogen flush, for hour, followed by like treatment under diminished pressure for hour.

The reaction product was treated at C. with 4%, by weight, of filtering clay and then filtered through 1%, by weight, of the clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 11.27% zinc and 3.60% phosphorus.

Example 12 DI-SECONDARY AMYLPHENOL-P205 (3:1) PRODUCT Reaction mixture: Grams Di-secondary amylphenol 1404 P205 285 Procedure.-The di-secondary amylphenol was placed in a 3-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and was heated to 100 C. The phosphorus pentoxide addition was made portionwise over a 3-hour period at 100 C. for eight hours. The clear amber reaction product was filtered through filtering clay contained on a heated Buchner funnel. The product contained 7.68% phosphorus and had an N. N. (potentiometric) of 165.

Example 13 NORMAL ZINC SALT OF DI-SECONDARY AMYLPHENOL- P205 (3 t 1) PRODUCT Reaction mixture: Grams Di-secondary amylphenol-P205 (3:1) product (Ex. 12) Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 270 ZnCO3 (100% excess) 50.2

Procedure-The di-secondary amylphenol-phosphorus pentoxide (3:1) product and the mineral oil were placed in a 1-liter, 4-necked, round-bottom flask equipped with i Example 1 4 NORMAL ZINC SALT OFDI-SECONDARY AMYLPHENOL- P205 (3 2'1) PRODUCT Reaction mixture:

Di-secondary amylphenol-PzOs (3:1) product Prcedure.-The di-secondary amylphenol-phosphorus pentaoxide (3: 1) product and the mineral oil were placed in a 5-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and the zinc acetate 'di-hydrate in alcohol solution was added thereto. The reaction mixture was heated with agitation to 165 C. with recovery'of alcohol-aqueous acetic acid condensate and then reacted at 165 C. for 1% hours under diminished pressure. mixture was cooled and filtered through filtering clay contained on a heated Buchner funnel. The filtrate, a dark amber colored oil, contained 3.38% zinc and 2.48% phos phorus.

Example COMPLEX ZINC ACETATE SALT OF DI-SECONDARY AMYLPHENOL-PaOn (3: 1) PRODUCT Reaction mixture:

Di-secondary amylphenol-PzOs (3:1) product (Ex. 12) "grams" 400 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) "grams" 800 Zn(C2H302)2.2H2O do 264 Ethyl alcohol, Formula ml 2500 Example 16 NONYL ALCOHOIrPzOs (321) PRODUCT Reaction mixture: Grams Nonyl alcohol (3,5,S-trimethylhexanol) 400 P205 128 Pr0ccdure.-The n'onyl alcohol was placed in a 1-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer, and mechanically driven stirrer and was heated with agitation to 100 C. and then the phosphorus pentoxide was added portionwise, keeping the temperature constant, over a two-hour period. The reaction mixture was maintained at 100 C. for four hours and then filtered through filtering clay contained on a heated Buchner funnel. The product contained 10.5% phosphorus and had an N. N. of 305.

Example 17 NORMAL ZINC SALT OF NGNYL ALCOHOL-P205 (3:1) PRODUCT Reaction mixture: Gra rns Nonyl alcohol-P205 (3:1) product (Ex. 16)---- 450 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 450 ZnCOs 170 Procedure-The nonyl alcohol-phosphorus pentoxide (3:1) product and the mineral oil were placed in a 3- The reaction mechanically driven stirrer.

'12 liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer andmechanically driven stirrer and the zinc carbonate was added thereto at room temperature. The reaction mixture was heated to 175 C. with recovery of water "of reaction and maintained at 175 C. 1- 50 C. for two hours. The reaction mixture was filtered through filtering clay contained on a heated Buchner funnel. The filtrate contained 7.67 7'0 Zinc and 4.82% phosphorus.

Example 18 COMPLEX ZINC ACETATE SALT OF NONYL ALCOHOL- P205 (321) PRODUCT Reaction mixture: Grams Nonyl alcohol-P205 (3:1) product (Ex. 16)... 400

lviineral oil (S. U. V. of sec. at 100 15.;

acid-refined Mid-Continent) 800 HCzHsOz (99.5%) (1 equivalent on basis of N. N.) 138 E5110 (2 equivalents 5%) 186 Procedure.The nonyl alcohol-phosphorus pentoxidc (3:1) product and one-half (400 grams) the final oil charge were placed in a 3-liter, 4-necl1ed, round-bottom flask equipped with a reflux condenser, thermometer and The acetic acid was added with agitation immediately followed. by the gradual acidition of the zinc oxide which caused a temperature rise. The reaction mixture was heated gradually and aqueous acetic acid was removed from the mixture by distillation. The reaction mixture was diluted with the second portion (400 grams) of mineral oil at C. to reduce the viscosity and was then heated to 165 C. and held at that temperature for one hour under diminished pressure. The reaction product was cooled and filtered through filtering clay contained on a heated Buchner funnel. T he product contained 10.6% zinc and 3.16% phosphorus.

Example 19 DI TERT-ATMYLPHENOL-PzzOs (3 :1) PRODUCT Reaction mixture: Grams Di-tert-amylphenol 2000 P205 405 Procedure-The di-tert-amylphenol was placed in a 5-liter, 4necl\'ed, round-bottom flask equipped with a rellux condenser, thermometer and mechanically driven stirrer. After heating to 100 C., phosphorus pentoxide was gradually added over-a six-hour period. The reaction mixture was then held between 90 C. and 100 C. for eight hours to insure complete reaction. The reaction product was filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 7.40% phosphorus and had an N. N. of 183.

Example 20 COMPLEX ZINC ACETATE SALT OF DI-TERT-AMYI.,- PHENOL-PzOs (3: 1) PRODUCT Reaction mixture: Grams; Di tert-amylphenol-PzOs (3: 1 product Ex.

19) 600 Mineral oil (S. U. V. of 100 56C. at 100 19.;

acid-refined Mid-Continent) -r 450 Zinc oxide a- 159 Acetic acid (glacial) 236 Procedure.The di-tert-amylphenol-phosphorus pentoxide (3:1) product and mineral oil were mixed in a 2-liter, 4-necked, round-bottom flask equipped with a condenser, thermometer and mechanically driven stirrer. Acetic acid was added followed by zinc oxide at room temperature and the reaction mixture was heated to C., during the course of which an aqueous acid distillate was collected, with the aid of an N2 flush. The reaction mixture was then held at 155 C. to C. under diminished pressure for one hour. Upon cooling to 100 C., the reaction product was filtered through filtering clay contained on a heated, Buchner funnel. The filtrate, rep- Example 21 NORMAL CADMIUM SALT OF OCTYLPHENOL-PaOs (3 1) PRODUCT Reaction mixture: Grams,

octylphenol-P205 (3:1) product (Ex. 5) 200 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 400 Cd(C2H302)2.2H2O 100 diminished pressure for one-half hour. After cooling to 100 C., the product was filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained7.1% cadmium and 2.65% phosphorus.

Example 22 COMPLEX CADMIUM ACETATE SALT OB OCTYLPHENOL- P205 (3 1) PRODUCT Reaction mixture: Grams octylphenol-P205 (3:1) product (Ex. 5) 100 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 100 Cd(C2HaO2)2.2H2O- 101 Prcedure.The octylphenol phosphorus pentoxide (3:1) product and mineral oil were added to a 1-liter, 4-

necked, round-bottom flask equipped with a reflux con-- denser, thermometer and mechanically driven stirrer and were heated to 70 C. The cadmium acetate dihydrate was added at 70 C. and the reaction mixture heated. Aqueous acetic acid recovery by distillation was com plete at 150 C. The reaction mixture was then heated. to and held at 165 C. for 1 /2 hours with nitrogen flush, /2 hour of which was under diminished pressure. The reaction product was cooled and filtered through filtering clay contained on a heated Buchner funnel. The

product contained 16.4% cadmium and 3.32% phosphorus.

Example 23 NORMAL MAGNESIUM SALT OF OCTYLPHENOL-PsOs (3:1) PRODUCT Reaction mixture: Grams octylphenol-P205 (3:1) product (Ex. 5) 200 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 400 MgCOs 33.3

Procedure.The octylphenol phosphorus pentoxide (3.1) product and the mineral oil were added to a 2-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and the magnesium carbonate was added at 80 C. The reaction mixture was then heated to and held at 165 C. for one hour and then filtered through filtering clay contained on a heated Buchner funnel. The fluid, amber- 1.4 colored product contained 1.15% magnesium and 2.44% phosphorus.

Example 24 COMPLEX MAGNESIUM ACETATE SALT OF OCTYL- PHENOL-PaOa (3 1) PRODUCT Reaction mixture: Grams octylphenol-P205 (3:1) product (Ex. 5) 150 Mineral oil (S. U. V. of sec. at 100 F.;

acid-refined Mid-Continent) 300 Mg(C2H3O2)2.4H20 122.5

Pr0cedure.-The octylphenol phosphorus pentoxide (3: 1) product and the first portion grams) of mineral oil were placed in a 1-liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and were heated to 40 C., whereupon the magnesium acetatetetrahydrate was added. The reaction mixture was heated with recovery of aqueous acetic acid by distillation and the second portion (150 grams) of mineral oil charge was added at 115 C. to reduce the viscosity of the reaction mixture. The reaction mixture was heated to and held at C. for 1% hours, the last /z hour being under diminished pressure. The reaction product was cooled and filtered through filtering clay contained on a heated Buchner funnel to give a product which contained 2.95% magnesium and 2.76% phosphorus.

Example 25 NORMAL COBALTOUS SALT OF OCTYLPHENOL-PaOs (3:1) PRODUCT Reaction mixture: Grams octylphenol-P205 (3:1) product (Ex. 5) 100 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 200 C0(C2H302)2.4H2O 46.7

Pr0cedure.-The octylphenol phosphorus pentoxide (3: 1) product and the mineral oil were placed in a 1-liter, 4-necked, round-bottom flask equipped with a reflux con denser, thermometer and mechanically driven stirrer and were heated to 50 C. at which time the cobaltous acetate tetrahydrate was added. Aqueous acetic acid was distilled oil to a reaction temperature of 165 C. and then the system was held at 165 C. for one hour under diminished pressure. The reaction product was cooled to 100 C. and filtered through filtering clay on a heated Buchner funnel. The filtrate, representing the finished product, contained 3.43% cobalt and 2.48% phosphorus.

Example 26 COMPLEX COBALTOUS ACETATE SALT OF OCTYL- PHENOL-PaOs (3:1) PRODUCT Reaction mixture: Grams octylphenol-P205 (3: 1) product (Ex. 5).. 100 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 200 C0(C2H3O2)2.4H2O 93.5

The reaction mixture was cooled Example 27 COMPLEX ZINC CAPROATE SALT OF OCTYLPHENOL P205 (3:1) PRODUCT Reaction mixture: Grams Octylphenol-PzOs (3:1) product (Ex. 5)--. Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid refined Mid-Continent) 100 ZnO 30.4 n-Caproic acid 86.5

Procedure.-The octylphenol phosphorus pentoxide (3: 1) product and the mineral oil were mixed in a 500- ml., 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and heated to 98 C.; whereupon the caproic acid was added followed by the. zinc oxide. The reaction mixture was heated to 175 C. with distillation of aqueous caproic acid. The reaction was continued for one hour at 200 C. under diminished pressure. the reaction product was filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 9.46% Zinc and 3.13% phosphorus.

Example 28' C14 ALKYLP-HENOL-PsOs (3 1) PRODUCT Reaction mixture: Grams C14 alkylphenol 2 300 P205 44.4

1 Oronite :1lky1phe11ol No. 14, a mixture of monoalkylated phenols, cons sting predominantly of para isomers, the alkyl l ps of which are branch-chained and contain an average of about 14 carbon atoms.

Procedure-The C14 alkylphenol was placed in. a 1- liter, 4-necked, round-bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer and heated to 100 C. Phosphorus pentoxide was added during the course of one hour, the temperature then being raised to C. and held there for four hours. The mixture was cooled and filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 5.43 phosphorus and had an N. N. of 148.

Example 29 COMPLEX CALCIUM ACETATE SALT OF C14 ALKYL- PHENOL-PaOs (3:1) PRODUCT Reaction mixture: Grams C14 alkylphenol-PzO's (3:1) product (similar to Ex. 28 with an N. N. of 1 27) 200 Mineral oil (S. U. V. of 100 sec. at 100 F.;

acid-refined Mid-Continent) 400 Calcium acetate monohydrate 80 Procedure-The C14. alkylphenol-phosphorus pentoxide (3:1) product and mineral oil were mixed in a 2-liter, 4-necked, round-bottom flask equipped with a condenser, thermometer and mechanically driven stirrer. Calcium acetate monohydrate was added at 80 C. and the mixture' heated to C. during the course of which an aqueous acetic acid distillate was collected with the aid of a nitrogen flush. The reaction mixture was then held at 155 C. to C. under diminished pressure for one hour. was filtered through filtering clay contained on a heated Buchner funnel. The filtrate, representing the finished product, contained 2.57% calcium and,l.60% phosphorus.

EVALUATION OF PRODUCTS.

To determine the ability of the complex salts of the Upon cooling to 100 C.

Upon cooling to 100 C., the reaction product invention as detergents in lubricating oils, engine tests were conducted on lubricating oil blends of small amounts of various representative complex salt products; and, for purposes of comparison similar tests were also carried out on oil blends of the normal salts and on the lubrieating oils per se. The tests used were the Lauson Detergency Test D-4 and the CFR Diesel Detergency Test D-21. The results of these tests are summarized in Tables I and II, respectively. The test procedures were as follows:

LAUSON DETERGENCY TEST D-4 Oil temperature, F 225 Jacket temperature, E 275 Speed, R. P. M 1825 Brake load, H. P 1.6

One-half throttle. 13-1 air-fuel ratio. Oiladded every 20 hours (one, gallon sample used).

The engine is inspected at the end of 20, 60 and 100 hours, the duration of the test being 100 hours. The fuel used is a controlled Mobilgas Special type blend gasoline (40% thermal+30% catalytically cracked+30% straight run-{-25 cc. TEL/gal.)

CFR DIESEL DETERGENCY TEST D-Zl This test determines the effectiveness of the lubricating oil in preventing piston deposits and top ring wear. A single cylinder CFR, 4-cycle, super-charged, diesel engine, is used. Theoperating conditions are as follows:

Oil temperature, F Jacket temperature, F 212 Speed, R. P. M 1800 Brake load, H. P 7.5 Oil addition every 8 hours starting at 4 hours (1 /2 gal.- sample-used). Heat input, B. t. u./min 1260 The duration of the test is 60 hours. The fuel used is a N0. 2 fuel oil containing 1% sulfur. The results are reported in terms of piston cleanliness ratings as in the D4'test.

From the data presented in Table l for the Lauson D-4 test, it will be seen that the complex salts in every instance provided marked improvement in the engine cleanliness rating over that of the corresponding normal salts. Also, the bearing weight loss in most instances is less for the complex salts than for the corresponding normal salts in this test.

The data in Table I] clearly show the superiority of the several complex salts tested, as detergents, over the corresponding normal salts in the CFR Diesel D-2l test.

For ready comparison, the metal and phosphorus contents of the various normal and complex salts prepared and tested as described herein are given in Table Ill. It will be seen that the phosphorus contents of the normal, and corresponding complex salts are practically the same, but that the metal contents of the complex salts are generally at least about twice that of the normal salts.

I balt, barium, calcium and strontium, in an amount sufliestates TABLE III Theoretical Percent Percent Example Percent Actual Metal Phosphorus No. Product Metal For Percent Equivalents Normal Metal in Excess Salt of Theory Theory Actual Complex Zlnc Acetate Salt of Wax- Zn-1. 10 Zn2.64 140 0.83 0.75

Phenol (314)Pa05 (311) Product.

Complex Zlnc Acetate Salt of Octyl- Zn3.84 Zn8.3li 118 2. 24 2.73

phenol-P105 (3:1) Product.

Complex Zinc Acetate Salt of Dl-Sec- Z113.09 Zn-6. 44 108 2.60 2. 45

amylphenol-PzOs (3:1) Product.

Complex Zinc Acetate Salt of Nonyl Zn-5. 56 Zn-l0.60 91 2.84 3.16

Alcol10lPzOs (3:1) Product. 4

Complex Zinc Acetate Salt of Dl-Tert- Zn-6. 76 Zn-IO. 7 86 3. 50 3. 71

amylphenol-P Oi (3:1) Product.

Complex Cadmium Acetate Salt of Cd-9.65 Cd-16.4 70 3.01 3. 32

Octylphenol-IHO; (3:1) Product.

Complex Magnesium Acetate Salt of Mg1.52 Mg2. 95 94 2. 60 2. 76

Octylpheno1P,O (3:1) Product.

Complex Cobalt Acetate Salt of Octyl- Co-3. 54 Co6. 74 90 2. 30 2. 46

phenol-P105 (3:1) Product.

Complex Zinc Caproate Salt of Octyl- Zn-5. 75 Zn9.64 64 3. 00 3. 13

phenol-P (3:1) Product.

Complex Calcium Acetate Salt of C14 Ca 1.60 Ca-2. 57 71 1.50 1.60

Alkylphenol-BO; (3:1) Product.

What is claimed is:

1. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent character of said oil, of a complex metal salt of a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of l) reacting one mol of phosphorus pentoxide with from about one to about three mols of an organic hydroxyaromatic compound that has an alkyl substituent having at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms. per molecule, to form an acidic, partial ester of phosphoric acid, and (2) reacting said acidic, partial ester of phosphoric acid with a metal salt reagent, the metal constituent of which is selected from the group consisting of zinc, cadmium, magnesium, co-

cient to furnish at least about two equivalents of metal per equivalent of acid-hydrogen content in said acidic, partial ester of phosphoric acid, and in which at least about one of said equivalents of metal is furnished'by a metal carboxylate selected from the group consisting of metal acetates and metal caproates.

2. A mineral lubricating oil containing a minor proportion, suflicientyto improve the detergent character of said oil, of a complex salt of a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (l) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof, to form an acidic partial ester of phosphoric acid, (2) reacting said partial ester with an amount of a zinc salt reagent sufficient to provide at least about one equivalent of zinc per equivalent of acid-hydrogen content in said partial ester, and (3) reacting the product obtained in step 2 with zinc acetate in an amount suflicient to provide at least one equivalent of zinc per equivalent of acidhydrogen in said partial ester.

3. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent character of said oil, of a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content; of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphenol, to form an acidic partial ester of phosphoric acid, (2) reacting said partial ester with an amount of zinc carbonate suflicient to provide at leastabout one equivalent of zinc per equivalent of acid 75 hydrogen content in said partial ester, and (3) reacting the product obtained in step 2 with zinc acetate in an amount suflicient to provide at least about one equivalent of zinc per equivalent of acid-hydrogen in said partial ester.

4. A mineral lubricating oil containing a minor proportion, suflicient to improve the detergent character of said oil, of a complex metal salt of a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of 1) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxy compound selected from the group consisting of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms, to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with a metal carboxylate selected from the group consisting of metal acetates and metal caproates, and in which the metal constituent is selected from the group consisting of zinc, cadmium, magnesium, cobalt, barium, calcium and strontium, in an amount sufficient to provide at least about two equivalents of metal per equivalent of acidhydrogen in said partial ester.

5. A mineral lubricating oil containing a minor pro portion, sufficient to improve the detergent character of said oil, of a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxy compound selected from the group consisting of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms, to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

6. A mineral lubricating oil containing a minor proportion, suflicient to improve the detergent character of said oil, of a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphenol to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

' 7. A mineral lubricating oil containing a minor proportion, suificient to improve the detergent character of said oil, of a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of nonyl alcohol to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

8. A mineral lubricating oil containing a minor proportion, suificient to improve the detergent character of said oil, of a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of di-secondary vamylphenol to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

9. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent character of said oil, of a complex cobalt salt of a partial ester of phosphoric acid having a cobalt content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxy compound selected from the group consisting of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms, to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of cobalt acetate to provide at least about two equivalents of cobalt per equivalent of acid-hydrogen content in said partial ester.

10. A mineral lubricating oil containing a minor proportion, .sufiicient to improve the detergent character of said oil, a complex cobalt salt of a partial ester of phosphoric acid having a cobalt content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphenol to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with an amount of cobalt acetate to provide at least about two equivalents of cobalt per equivalent of acid-hydrogen content in said partial ester.

11. As a new composition of matter, a complex metal salt of a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of l) reacting one mol of phosphorus pentoxide with from about one to about three mols of an organic hydroxy compound selected from the group consisting of a hydroxyaromatic compound that has an alkyl substituent having at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least '8 carbon atoms per molecule, to form an acidic, partial ester of phosphoric acid, and (2) reacting said acidic, partial ester of phosphoric acid with a metal salt reagent, the metal constituent of which is selected from the group consisting of zinc, cadmium, magnesium, cobalt, barium, calcium and strontium, in an amount sufiicient to furnish at least about two equivalents of metal per equivalent of acid-hydrogen content in said acidic, partial ester of phosphoric acid, and in which at least about one of said equivalents of 22 metal is furnished by a metalv carboxylate selected from the group consisting of metal acetates and metal caproates.

12. As a new composition of matter, a complex saltof a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof, to form an acidic partial ester of phosphoric acid, (2) reacting said partial ester with an amount of a zinc salt reagent sufncient to provide at least about one equivalent of zinc per equivalent of acid-hydrogen content in said partial ester, and (3) reacting the product obtained in step 2 with zinc acetate in an amount sufiicient to provide at least one equivalent of zinc per equivalent of acid-hydrogen in said partial ester.

13. As a new composition of matter, a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphenol, to form an acidic partial ester of phosphoric acid, (2) reacting said partial ester with an amount of zinc carbonate sufi oient to provide at least about one equivalent of zinc per equivalent of acid-hydrogen content in said partial ester, and (3) reacting the product obtained in step 2 with zinc acetate in an amount sufiicient to provide at least about one equivalent of zinc per equivalent of acidhydrogen in said partial ester.

14. As a new composition of matter, a complex metal salt of a partial ester of phosphoric acid having a metal content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (l) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxy compound selected from the group consisting of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms, to form an acidic, partial ester of phosphoric acid, and (2) reacting said partial ester with a metal carboxylate selected from the group consisting of metal acetates and metal caproates, and in which the metal constituent is selected from the group consisting of zinc, cadmium, magnesium, cobalt, barium, calcium and strontium, in an amount sufiicient to provide at least about two equivalents of metal per equivalent of acid-hydrogen in said partial ester.

15. As a new composition of matter, a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of 1) reacting one mol of phosphorus pentoxide with from about one to about three mols of a hydroxy compound selected from the group consisting of a hydroxyaromatic compound having an alkyl substituent of at least 8 carbon atoms in place of a nuclear hydrogen atom thereof and a primary, aliphatic alcohol having at least 8 carbon atoms, to form an acidic, partial ester of phosphoric acid and (2) reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

16. As a new composition of matter, a complex zinc salt of a partial ester of phosphoric acid having a zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphenol to form an acidic, partial ester of phosphoric acid, and (2) reacting: said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

17. As a new composition of matter, a complex zinc salt of a partial ester of phosphoric acid having a zinc contentgreater than that which would be equivalent to the acid hYdrOgen content of said partial estei prepared by the steps of (1) reacting one mol' of phosphorus pentoxide with about three mols of nonyl alcohol to form anacidic, partial ester of phosphoric acid; and (2') reacting said partial ester with an amount of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester. 18. As anew composition of matter, a complex zinc salt of a;- palt-ial ester of phosphoric acid having a Zinc content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of di-secondary amylphenol to form an acidic, partial ester of phosphoric acid, and 2 reacting said partial ester with an amount .Of zinc acetate to provide at least about two equivalents of zinc per equivalent of acid-hydrogen content in said partial ester.

19. As a new composition of matter, a complex cobalt salt ofa partial ester of phosphoric acid having a cobalt .content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxid with tram ahout on oout th ee mp1s ot a hydroxy compound selected fromthe group copsisp s of a y oxy roma c p und av n an a ky substituent of at least 8- carbon atoms in place of a npclear hydrogen atom thereof" and a primary, alipha ic alcjohol having at least 8 carbon atoms, tofform an acidic, partial ester of phosphoric acid, and (2)' reacting said partial ester with an amount of cobalt acetate to provide at least about two equivalents of cobalt per equivalent of acid-hydrogen content in said partial ester.

20. As a new composition of matter, a complex cobalt salt of a partial ester of phosphoric acid having a cobalt content greater than that which would be equivalent to the acid-hydrogen content of said partial ester, prepared by the steps of (1) reacting one mol of phosphorus pentoxide with about three mols of octylphe'nol to form an acidic, partial ester of phosphoric acid, and, (2), reacting said partial eater with an amount of cobalt acotate to provide at least about two equivalents of cobalt per equivalent of acid-hydrogen content in said partial ester.

References Cited in the file of this patent UNITED STATES PATENTS 2,228,659 Farrington et al. Jan. 14, 1941 2,346,155 Denison et'al. Apr. 11, 1944 2,378,820 A'mott June 19, 1945 2,745,863 Otto May 15, 1956 

1. A MINERAL LUBRICATING OIL CONTAINING A MINOR PROPORTION, SUFFICIENT TO IMPROVE THE DETERGENT CHARACTER OF SAID OIL, OF A COMPLEX METAL SALT OF A PARTIAL ESTER OF PHOSPHORIC ACID HAVING A METAL CONTENT GREATER THAN THAT WHICH WOULD BE EQUIVALENT TO THE ACID-HYDROGEN CONTENT OF SAID PARTIAL ESTER, PREPARED BY THE STEPS OF (1) REACTING ONE MOL OF PHOSPHORUS PENTOXIDE WITH FROM ABOUT ONE TO ABOUT THREE MOLS OF AN ORGANIC HYDROXYAROMATIC COMPOUND THAT HAS AN ALKYL SUBSTITUENT HAVING AT LEAST 8 CARBON ATOMS IN PLACE OF A NUCLEAR HYDROGEN ATOM THEREOF AND A PRIMARY, ALIPHATIC ALCOHOL HAVING AT LEAST 8 CARBON ATOMS PER MOLECULE, TO FORM AN ACIDIC, PARTIAL ESTER OF PHOSPHORIC ACID, AND (2) REACTING SAID ACIDIC, PARTIAL ESTER OF PHOSPHORIC ACID WITH A METAL SALT REAGENT, THE METAL CONSTITUENT OF WHICH IS SELECTED FROM THE GROUP CONSISTING OF ZINC, CADMIUM, MAGNESIUM, COBALT, BARIUM, CALCIUM AND STRONTIUM, IN AN AMOUNT SUFFICIENT TO FURNISH AT LEAST ABOUT TWO EQUIVALENTS OF METAL PER EQUIVALENT OF ACID-HYDROGEN CONTENT IN SAID ACIDIC, PARTIAL ESTER OF PHOSPHORIC ACID, AND IN WHICH AT LEAST ABOUT ONE OF SAID EQUIVALENTS OF METAL IS FURNISHED BY A METAL CARBOXYLAT SELECTED FROM THE GROUP CONSISTING OF METAL ACETATES AND METAL CAPROATES. 